1. Field of the Invention
The present invention generally relates to a vehicle brake device. More specifically, the present invention relates to a vehicle brake device that controls a braking force of the vehicle in accordance with the target deceleration rate.
2. Background Information
One example of a conventional vehicle brake device is disclosed in Japanese Laid-Open Patent Application No. 11-301434. This publication discloses a conventional vehicle brake device in which a target deceleration rate is calculated based on a master cylinder pressure and a brake pedal stroke, and the braking force of a vehicle is controlled in accordance with the target deceleration rate. A contribution ratio or a degree to which the master cylinder pressure and the brake pedal stroke contribute to the target deceleration rate varies according to at least one of the master cylinder pressure and the brake pedal stroke. The contribution ratio is set such that the degree to which the brake pedal stroke contributes to the target deceleration rate is relatively large particularly when the brake pedal is initially depressed. This is due to a general tendency among drivers to adjust the braking force primarily by adjusting the brake pedal stroke when a low deceleration rate is desired, and to adjust the braking force primarily by adjusting the pedal depression force (pedal depression pressure) when a high deceleration rate is desired.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved vehicle brake device. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.